Welsh welterweight Evans outclasses a game Algerian in Ilyas Abbadi to outscore him 18-10 on Sunday afternoon.
And that evening, Scottish lightweight Taylor saw off Brazil’s Robson Conceicao despite later claims from the defeated participant that the partisan home crowd had influenced the judges’ scoring.
The duo, both 21, join stablemate Agogo in the second round after the English middleweight defeated Junior Castillo Martinez on Saturday.
“I haven't experienced that sort of atmosphere before, with everyone screaming for me, and it put me on a high, it was one big buzz," said Evans.
"The only time I've seen a crowd like that before was at big pro fights.
"I started swinging at times but that was just a bit of ring-rust, and maybe the crowd getting me going a little bit and me getting a bit overexcited.
"But that should sharpen me up now for the next fight."
Evans faces fourth seed Egidijus Kavaliauskas on Friday, and hopes to avenge a loss to the Lithuanian at the World championships.
"When he beat me in the Worlds it was after my [Olympic] qualification fight so I was switched off completely," he admitted.
"But this time I'm looking at medals and he'll see a different fighter.
"He's good, he won bronze at the Worlds, but he suits me - he's a short, strong, come-forward fighter, nothing I haven't faced 100 times before."
"The tactics were just to box and move, keep it long, and that's what I did," said Taylor, who now faces third seed and former world champion Domenico Valentino.
"It felt very close but I thought I'd won it and was in control. I wanted to give the crowd a bit of a thrill but it's not about that, it's about winning the fight.
"I'll do exactly the same against Valentino, keep it long and box him."
Conceicao claimed he was the victim of biased judging following defeat.
Conceicao, who pushed world amateur champion Vasyl Lomachenko all the way in last year's championships, was convinced he won every round.
"They (the judges) were very malicious. It's not fair because I think the judges favoured him because of the crowd and that shouldn't happen in a competition like this," Conceicao said following the fight.
"It hurts a lot, I was fighting really well, making the points and the referees didn't give it. I'm sad."
In front of a packed and giddily excited arena, Taylor became the third British boxer in a row to advance to the second round of this year's Games, handing rising boxing power Brazil its first defeat in the process.
"It will be very difficult," Conceicao said when asked if it would be hard to beat a British boxer in London.
Taylor, who sparred with the Brazilian in what he described a tough session in the run up to the Games, said it was amazing having the crowd behind every punch he threw, describing the experience as the best in his life.